Semiconductor laser device

Abstract

A semiconductive laser device having a resonator which is formed with a dielectric film on at least one end face thereof is described. The dielectric film is in a thickness of at least three times a wavelength in the dielectric film by which the oscillation wavelength becomes very stable.

What is claimed is: 
     
       1. A semiconductive laser device of the type which comprises at least one optical resonator having a dielectric film formed on at least one end face of the resonator from which a laser beam is emitted, said dielectric film having a thickness which is not less than three times a wavelength of the laser beam in the dielectric film whereby the oscillation wavelength of the semiconductive laser is stabilized. 
     
     
       2. A semiconductive laser device according to claim 1, wherein said dielectric film is made of aluminium oxide. 
     
     
       3. A semiconductive laser device according to claim 1, wherein said dielectric film is a multi-layered structure wherein at least one layer of the multi-layered structure has a thickness of not less than three times the wavelength. 
     
     
       4. A semiconductive laser device according to claim 3, wherein said multi-layered structure is a two-layered structure having two layers made of different dielectric materials. 
     
     
       5. A semiconductive laser device according to claim 4, wherein said two layers are made of Al 2  O 3  and TiZrO 4 . 
     
     
       6. A semiconductive laser device according to claim 5, wherein the layer of TiZrO 4  directly contact the end face. 
     
     
       7. A semiconductive laser device according to claim 1, further comprising another dielectric film formed on the other end face of said resonator. 
     
     
       8. A semiconductive laser device according to claim 7, wherein the dielectric film formed on the opposite end faces has a multi-layered structure. 
     
     
       9. A semiconductive laser device according to claim 1, wherein two resonators are provided and have a dielectric film on a beam emission end face of each resonator in such a way that the thicknesses of the respective dielectric films are substantially equal to each other. 
     
     
       10. A semiconductive laser device of the type which comprises a plurality of optical resonators at least one of which has a dielectric film formed on at least one end face of the at least one resonator from which a laser beam is emitted, said dielectric film having a thickness which is not less than three times a wavelength of the laser beam in the dielectric film whereby the oscillation wavelength of the semiconductive laser is stabilized. 
     
     
       11. A semiconductive laser device according to claim 10, wherein the plurality of the optical resonators have, respectively, on at least one beam emission end face dielectric films having different thicknesses of not less than three times the wavelength.